1. Field of the Invention
The present invention relates to a technique which is effective when applied to a thin-film releasing technique for releasing a thin film stuck on a substrate and for drawing off the released thin film.
2. Background of the Prior Art
Generally, printed-wiring substrates used in electronic appliances, such as computers and the like, are provided by forming patterned wirings of copper or the like on opposite sides (or one side) of an insulating substrate.
Printed-wiring substrates of this type can be produced by the following manufacturing process. First, a lamination composed of a light-sensitive resin (photoresist) layer and a transmission resin cover film (hereinafter simply referred to as a "cover film") for protecting the light-sensitive resin layer is laminated onto an electrically conductive layer of an insulating substrate by thermocompression. After thermocompression lamination, a wiring pattern film is overlapped on the substrate so that the light-sensitive resin layer is exposed to light for a predetermined period of time through the wiring pattern film and the cover film. After the cover film is released from the substrate, the exposed light-sensitive resin layer is developed to form an etching mask pattern. After development, the unnecessary portion of the electrically conductive layer is removed by etching and then the residual part of the light-sensitive resin layer is removed, so that a printed-wiring substrate having a predetermined wiring pattern is prepared.
In the aforementioned process of manufacturing printed-wiring substrates, a step of releasing the cover film is necessary when the exposed light-sensitive resin layer is developed. The releasing of the cover film has depended on human workmanship. Since the cover film is very thin, it requires dexterous fingers and a great deal of skill to prevent damage and destruction of the light-sensitive resin layer due to distortion of releasing stress.
To eliminate overcome these disadvantages, an automatic thin-film releasing apparatus for performing the thin-film releasing process mechanically and automatically has been developed. The automatic thin-film releasing apparatus is provided to release an upper-side cover film automatically by blowing fluid against a loose portion of the cover film which portion is loosened by loosening means, such as a needle, a brush, a knurling tool or the like. The released portion of the cover film released by blowing fluid is attached on a releasing-direction setting plate to be kept thereon, and then the partially released cover film stuck on the substrate is conveyed while being completely released from the substrate by a thin-film conveyance system. The thin-film conveyance system is constituted by two belt conveyers capable of nipping the cover film for releasing and conveying the cover film from the substrate. The thin film conveyance system is connected to the automatic thin-film releasing apparatus or installed within the latter. The cover film conveyed by the belt conveyers of the thin-film conveyance system is conveyed to an exhausted thin-film receiving vessel.
An automatic thin-film releasing apparatus as disclosed in Japanese Patent Application No. 61-388880 (1986) previously filed by the same Applicant of this application has two exhausted thin-film receiving vessels arranged in upper and lower sides of the conveyance path of the substrate. The lower-side cover film on the lower surface of the substrate is conveyed into the lower-side exhausted thin-film receiving vessel. The upper-side cover film on the upper surface of the substrate is conveyed into the upper-side exhausted thin-film receiving vessel. In the thus arranged automatic thin-film releasing apparatus, the exhausted thin-film receiving vessels can be arranged in three dimensions to make it possible to realized miniaturization of the apparatus.
The upper-side cover film on the upper surface of the substrate is conveyed to the upper-side receiver portion of the upper-side exhausted thin-film receiving vessel by the belt conveyers of the thin-film conveyance system, whereafter the cover filmm is exhausted. The belt conveyers are operated while nipping the cover film. Accordingly, the belt conveyers must be long corresponding to the height of the upper-side exhausted thin-film receiving vessel. Therefore, fine distortion of tension is often produced between the belts opposite to each other with respect to the cover film. As a result, a problem arises in that the belt-conveyers often experience problems such as jamming or the like.
Further, the upper-side exhausted thin-film receiving vessel must be arranged in a position higher than the conveyance path of the substrate. Accordingly, handling of the upper-side exhausted thin-film receiving vessel is troublesome in areas, such as disposal of waste cover films. As a result, the ability to work on the receiving vessel is reduced. Particularly, in the case where the exhausted thin-film receiving vessel is formed of a metal material, such as stainless steel or the like, the workability is remarkably lowered due to the excessive weight of the exhausted thin-film receiving vessel.
It is therefore an object of the present invention to provide a technique by which conveyance problems of the released thin film can be reduced in a thin-film releasing apparatus in which the thin film stuck to the substrate is conveyed and exhausted while the thin film is simultaneously released from the substrate.
It is another object of the invention to provide a technique by which conveyance problems of the thin film caused by the occurrence of electrostatic energy can be reduced as well as the aforementioned object attained.
It is a further object of the invention to provide a technique by which the yield of products can be improved.
It is also an object of the invention to provide a technique by which handling of the exhausted thin-film receiving vessel can be improved and conveyance difficulties of the released thin film can be reduced in a thin-film releasing apparatus in which the thin film stuck to the substrate is conveyed so as to be exhausted into the exhausted thin-film receiving vessel while the thin film is released from the substrate.
It is also a further object of the invention to provide a technique by which handling of the exhausted thin-film receiving vessel can be improved and conveyance troubles of the released thin film can be reduced, and by which miniaturization of the apparatus can be attained, in a thin-film releasing apparatus in which the thin films stuck to opposite sides of the substrate are conveyed to be exhausted to the exhausted thin-film receiving vessel while the thin films are released from the substrate.
The foregoing and other objects and features of the invention will be apparent from a reading of the specification and the accompanying drawings.